Nowadays, much consideration is given to a search for and a study for of antiviral, interferon-inducing and immunomodulatory agents. A special attention focuses on agents which are capable of modulating, potentiating or inhibiting a body's immune reactions--immunomodulators.
Immunomodulator increase a general body resistance effecting specific immune reactions and nonspecific defensive factors including an endogenous interferon production. They are used for treating diseases in pathogenic mechanisms of which disorders of a body immune status play an important role--primary and secondary immunodeficiency conditions including cancers as well as chronic and relapsing virus infections.
Among a few synthetic chemicals used as immunomodulators the most effective and widely used in the clinical practice is levamisole/(-) 2,3,5,6,-tetrahydro-6-phenylimidazo-/2.1.b/-thiazole hydrochloride/. /A.D. Mashkobsky, Lekarstvennye sredstva, 1987, (Moskva), "Meditsina", v. 2, pp. 169-171/.
Levamisile as an immunomodulator is used in a complex therapy of various diseases associated with immunodeficiency conditions. The use of levamisole for treating severe retroforms of herpes virus infection is disclosed in literature. Levamisole as well as some other immunomodulators stimulates the production of serum interferon in the body. The interferon titers, produces by the action of levamisole are not over 80-160 U/ml in a cell culture; 160-320 U/ml in the mouse blood serum and 40-80 U/ml in the human blood serum.
However, levamisole is highly toxic and may cause various side-effects; a headache, sleep disturbances, olfactory hallicinations (odour changes), allergic skin hypersensitivity, influenza-like and neurologic symptoms.
The most prejudicible side-effect which may take place in the treatment by using levamisole as an immunomodulator is agranulocytosis--the decrease of neutrophile to a value below 25%. Therefore, the blood should be systematically assayed during the treatment with levamisole.
At present, antiviral drug preparations are also known to contain adamantane derivatives as an active principle, for example, remantadine (alfa-methyl-1-adamantanemethylamine hydrochloride)/Mekhanizmy antivirusnogo deistvia proizvodnykh adamantana, 1982, (Riga) "Zinatne", pp. 25-29, 129-141/. These preparations have a side-effect on a central nervous system.